Ryan – sorry for delay!
First thing – what connector do you have going in to the back of the trip computer? It needs to be a double 15 terminal connector. If you only have a single 15 connector then that is a problem already. I only had a single 15 connector in my car but managed to get another single one from a wreckers and join them together (after cutting some lugs off) so I would have access to all 30 terminals on the trip computer.
It does sound like your wiper switch isn’t actually connected to the unit. One wire in the switch needs to connect to terminal 5 on the bottom row of the unit (numbered from left to right) and the other needs to connect to earth. You will need to check if this wiring is in place.
Terminal 2 on the bottom row needs to connect to earth.
Terminal 10 on the bottom row is for speed data input. For this I spliced a wire into the speed data wire that goes into the instrument panel. On my car this wire is a brown wire, numbered 465 and enters the instrument panel through terminal 21 of the large yellow connector on the back of the panel. I took the connector apart to make sure I got the right wire and used a red ‘scotchlock’ connector to splice in to it.
Terminal 12 on the bottom row is for fuel flow data input. This needs to be connected to the main ECU in the engine compartment. On my car, which has a Bosch MP5.1.1 system, I spliced in to the wire coming from terminal 4 on the ECU, numbered 1368. Although I found this wire did lead to a connection block under the battery, I decided to splice into it near where it came out of the ECU. It did mean stripping back the connector, again to make sure I had the right lead and also to be able to splice into it. From here I took it through to the gap where the wiper motor sits, passing it through the same hole as the wiper motor wiring. Then took it along to the air blower inlet and dropped it through to the passenger footwell, making sure it was clear of the blower blades.
Terminals 13 and 14 on the top row of the unit are for the fuel gauge data. For this you do need to cut the wire that comes from the fuel gauge. On my car this wire again enters the instrument panel through the large yellow connector at terminal 11. It is a brown wire, numbered 4315. It needs to be cut (not too close to the instrument panel!) with the end from the fuel gauge connecting to terminal 14 and the end from the instrument panel connecting to terminal 13. You will obviously have to extend the wires to reach the trip computer.
There is one other connection that is shown on the Haynes diagram, which is connecting terminal 6 on the bottom row of the unit to terminal 15 on the yellow connector on the instrument panel. It is still a mystery to me what this lead does as everything seems to work fine without it. It is labelled as lead 4310 on the diagram – the 43 prefix means it is to do with fuel data, but all it seems to do is connect to a defunct bulb socket on the instrument panel.
I assume you already have all other wiring needed as you have your temp display working. You will need to adjust the little switch on the side of the unit once all wiring is in place, depending on whether you want stereo information displayed also.
It is a bit of a project but very worthwhile once it’s all working! Let me know if you need any further info!
Steve
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